Another Dave masterpiece. You never cease to amaze us with your knowledge and teachings. We are fortunate to have you in the industry. Pure genius my friend. Thank you for sharing this with us Dave.
This visual way of comprehending signal flow is great! It's like looking at puzzle pieces on a table, and when you see them all layd out, its then you see it. "Oh look at that, if I put this here and that there I can do this!! Its a great way to visualize the capability of your equipment before disconnecting and rearranging gear. Thank you Dave for sharing !
This is a perfect example of your philosophy and approach to live sound, learning from you has been such a treat, Dave! Thanks for this, love the visuals.
Oh man, I remember how excited I was when first got my greedy hands on bi-amp capable speakers, and then realized that I didn't have a second amp available to drive it, or a crossover... Lol Then I ended up with some sub-bass cabinets and extra amp channels, but the sub-bass processor was dead, so I emulated it in the system processor to drive them, and FINALLY had the kind of bass I wanted!
I'm 56 seconds in already hitting the like button because I know something good is coming BUT ALSO how accessible the cardboard drawings are "I have cardboard and a sharpie!"
These are the videos I would have needed 20 years ago when I started to learn. Very nice visualization, easy to understand and nicely explained. I hope the new generation of audio engineers finds your channel as useful and eye opening as I do.
Just needed to explain all this to a newcomer to the pa scene and up you pop like a genius Aladdin with the magic lamp. Thanks for making a hard task easy for me. Pure fun pure 😊genius!
Wow! This video is another super valuable vid you put out here! I could see it used, not only to unexperienced sound engineers, but also to non-tech people who need to understand why it is important to invest money in a proper installation This is so simple that anyone who's a little bit interested in sound reinforcement can understand it. Props to you Dave!
I saw Kiss at the FedEx Forum in Memphis a couple of years ago. My wife and i could talk to each other through the whole show. Sound system didnt have any balls. I remember the rigs of the 80s. The concrete in the arena would shake. The mids would make the body alive with energy. And the highs would literally make your eyes go crossed when the singer hit the right note. I miss that.
Sounds like you were mighty unlucky and got a seat in a weak area of the sub's coverage. I hate when that happens, I saw Yes play the Paramount in Denver 10 years ago, and it was a similar situation. But we just moved down the row to some other empty seats, and it was fine.
Modern systems higher fidelity, smaller, lighter, louder, offer better sightlines and greatly improved coverage than the older systems. That said, band budget and the quality of the sound engineer will be the true determining factors of the audience audio experience. Modern shows can sound amazing in ways older systems could never achieve
Thanks Dave I've watched a lot of your videos but this is the first time that I've commented on. It's not because you're not telling the truth or anything like that, it's because this one is so simple for younger people coming up.
I kind of did this to clarify and add foundation to the subs on aux. People that are anti or reluctant or unclear on subs on an aux should understand more about how it is a natural progression
*Insert clever comment here* Really nice video Dave. Even as someone who has used systems this was a really nice overview/refresher of all the parts that go into a sound system.
I just stumbled across this video and although my goal is not live sound, I love your style of teaching, especially with those cards! I've been trying to find good content from experienced sound engineers to pick up audio engineering skills to help my composing and music production, and your videos are great!! Thank you!
Well explained. I have complicated systems but one I have at home that gets a bit of use is Source-SET amplifier-Fullrange driver horn 1 driver no networks. So simple but its sure can reveal the soul in sound.
Deadly, so simply communicated!! Would love to see a practical application with actual gear mapped put in the same way to put in in a practical sense :) nothing beats theory and practice put together!! Thanks Dave ye legend
All my vids tease to channel members first and I released them in reverse order publically do no particular reason. The follow up vid is ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-hpFK1XOZuUg.html
Great video. I'll definitely be sending it to people who have questions. I know you've been talking about concert systems, however it feels like manufacturers of DJ sized powered speakers have been dropping biamplification. Unless I'm misreading the specs, this seems to be the case for JBL's IRX100, EON700 and PRX900 lines. The PRX800 mentioned being biamped in the specs so not mentioning it for the new equipment seems suspicious. A cursory look at the new offerings from EV, Mackie, Yamaha, etc. seem to show the same trend (only RCF still mentions biamplification but they're out of my price range). Is there a reason for this trend? Does it impact the quality of the output?
For well processed and protected systems with sufficient amp power where the amp never clips, passive can work really well. So these are baselines but there are many factors
Dave I have to say, after 10 years of doing things the "standard" way, you've got me excited to experiment with matrix fed subs! I was weary of it for a lot of the standard reasons people talk about (like the x-over point changing if the sub send level is changed and potentially confusing fill in engineers who may not be in the know when it comes to this), but I can't ignore the benefits you describe in your videos. I have an interesting Friday ahead of me at the venue methinks, it's time for me to try a maxtix fed sub setup :)
What I learned: although there are bunch of EQ filters, they can't completely cut all the frequencies it is aupposed to...Not even the from the main output!
Correct and the steeper the filter and the more you cut out the worst it sounds because of filter ringing and phase shift. The softer the filter and the less you cut out the better it sounds but the less control you have
I think the one only case where subs on an aux might not be ideal is on rigs where the tops are high passed pretty high, like 100Hz or more. In that case, you might not get as much low end as you want on channels only routed to the tops. Not an issue with big PA of course. But there have been a couple of occasions on other people's rigs where I wound up having to dial evan vocals into the subs to 'warm them up' after configuring aux subs, and a full range rig would have been ok.
I agree they would be less effective with a system that has a higher crossover to the mins as you would put more instruments in the subs. That said, if you are able to eliminate 1/2 the inputs or even 25% from the subs, that is still a gain. Hh, oh, BG vox, sn bottom are all good contenders
@@ashergregory2013 with the system like that, I would want to have another box to cover from say 45 to 125, and then subs to cover below that. It’s kind of a pain to have to add another band-pass of speakers, but it would give you a lot more control. Not to mention that subs sound better when they don’t have to go up that high where they sound boxy and directional.
Main reason I dont prefer aux fed subs is you cant process the low end with the same processing as the mains. For instance, buss compression or multiband compression that I like on my entire mix. To me it makes things much more complicated. I like to mix like the way I mix in my studio. I suspect your preference for it Dave has to do with your experience on very large systems. Also, most of what I mix is church gigs which with no amps onstage. Guitars and bass all DI and drums typically enclosed in a cage, and if not still the only thing producing any low end onstage. I suspect if i had multiple amps onstage at concert volume I might be more interested in aux fed subs.
Interesting. Isn't multibrand compression a complex way of trying to prevent the subfrequencies from creating pumping sounds on the upper ranges? Subs on an aug send eliminates his issue perfectly instead of dividing things up compressing the low separately and then recombining them electronically like a multi-band compressor does. Subs on an auxend allow you to compress the subs separately and independently and recombine the signals acoustically. It's not the tool for every job but it definitely gives you more control and a less processed sound
@@DaveRat yessir that is indeed one main usecase for them. But I use multiband compression moreso for getting a specific sound. I suppose its just been part of my workflow for so long. Ive never felt i had too much rumble or low end *noise in well installed PAs so when ive come across aux fed subs it felt like more of a pita than anything lol though i know many pro engineers who love them. As for compressing the low end on its own, ive done that as well but it felt clunky and was more to manage than just monitoring my LR buss processing. Caveat for me is ive never worked on anything bigger than maybe 1000 seat clubs/churches so i cant speak to massive PAs etc…..
@LaminarSound I've done several other videos on subwoofers on an aux that may provide more useful information. Ultimately it's about control. Let me provide a few scenarios 1) an engineer has all the instruments sent to left and right 2) The engineer has all the instruments Santa left and right but the subwoofers are on stereo auxiliary sends from each channel such that the EQ and fader levels affect that auxiliary send. Control and mixing is identical to scenario 1. Any EQ or processing that is on the left and right is also mirrored and put on the left and right subwoofer sends. The subwoofers ends from each channel are sent with the exact same panning as they are in scenario 1. For all practical purposes scenario one and scenario 2 sound exactly the same. I now walk up behind that engineer while they're mixing and ask " why do you have the hi-hat sent to your subwoofers?" Why do you have your overheads sent to your double 18 subwoofers? Why do you have your vocal mics sent to your subwoofers and I hear these big pee pops that you are now high passing but it isn't getting rid of all of it without taking away some of the warmth of the vocal? So the engineer starts turning down the subwoofer sends on the channels that don't need subwoofers. We then both look at each other and go wow that sounds cleaner and clearer And then we smile
Let me present a few scenarios Scenario 1 The engineer as all of the instruments sent directly to left and right which then drive the left and right main speakers as well as the left and right subwoofers Scenario 2 The engineer has all the instruments sent to the left and right main speakers and has a separate stereo sand on each channel that sends to the subwoofers and pans exactly the same way as the sends to left and right. In both scenarios the EQ and left and right processing is identical and on the second scenario the left and right subwoofers are processed by mirrored versions of that same left right processing For all practical purposes both of these scenarios sound exactly the same and mix exactly the same. I then Walk up behind that engineer and ask " why do you have hi-hat and overheads sent to the subwoofers?" Do you really need your vocals sent to the subwoofers? I hear a lot of p pops and I see you've got your high pass filters set pretty high to get rid of them but that seems to be taking some warmth out of the vocals that you're now EQing back in doesn't that seem kind of awkward? What if you don't send any instruments to the subwoofers that you don't want subwoofers on? And the engineer goes through and turns down the subwoofer sends on all the instruments they don't want subs on. Wow that sounds clear and cleaner! Omg I have more control now I can determine how much subwoofer I want on each instrument versus how much I use the high pass. This is like having a whole other level of EQ! Wow that wind noise it's getting into all those mics that I don't need subwoofers on and I've been high-passing to get rid of wind noise Sound warmer and clearer and I have less wind noise and a better sound, cool! And then we both smile and hang out
@@DaveRat That is a valid point Dave and I cant disagree. Id never tell someone if it's working for them to not do it. Especially not the GOAT Mr. Rat! I just work from my own experience. Ive not had issues with vocal mic plosives or wind noise coming through my subs and causing any problems, or a lack of warmth in my vocal mics from trying to EQ out those plosives. Again, ive not mixed many shows outdoors, and definitely havent mixed shows anywhere near the sizes you have. So thats a big caveat I think. When ive come into venues with aux fed subs I always had issues like not near enough top end in my kick drums or bass guitars, and I know good and well what a D6 sounds like on a well tuned kick drum, and what 3.5khz sounds like on a bass guitar. Most of the time this is because they just sent kick and bass straight to the sub and not the mains. Other times it has been poor calibration of the tops vs the subs, and send levels all varying. I didnt have time to address these issues. I just wished I had a balanced LR to work with and not have to dive into routing or sends to troubleshoot. I do have a serious question for you Dave.. if all stereo music is mixed down today to just an LR, and those songs all sound great when pumped through a live PA, shouldnt you be able to duplicate those results without aux fed subs??? That stuff wasnt mixed on aux fed subs in the studio and those kicks and bass guitars arent being split out from the 2 track when played back. Most consoles nowadays have multiband compressions and limiting built in. In addition to most of the other tools one might use in a studio mixing session.
Summing amps and buffer amps are everywhere in the analog audio path and similar. The polarity reverse is usually just a polarity inverting buffer amp. When you assign at left and right or an aux, you are sending to a summing amp With digital kits different and more of a math equation.
Just wondering what your take is on the Wall of Sound that the Grateful Dead used in the mid '70s. They took this to a pretty extreme level (at one point Phil Lesh had a separate amp/speaker stack for each string on his bass), but things like their phase-matched differential microphone pairs for the vocals strike me as an elegant solution to reduce or eliminate bleed and feedback.
Well if you really want to know my thoughts on that and are up for diving into a rabbit hole, try a Google search on Dave rat double hung PA wall of sound and there is loads of information on not only when I built a mini wall of sound on Black Flag tour as well as toured with a streamlined version that worked very well solving many of the problems with the wall of sound with a modern day system. Also I have much info on minimizing multiple sounds from single sources the same sound from multiple sources having issues and numerous other perspectives. Not sure what you'll find but I think there's more than most humans could possibly ingest on the subject
Without even seeing the experiment, I know the HPFs are gonna let in plenty of bass. I frequently mix on a system with subs on crossover, and when the keys player hits a low octave it's impossible to get that bass out of the subs. We have to resort to 150hz or higher HPF and still some comes through. The bass players hate it.
Yeah, either raise the high pass too high and sound bad or send bass bleeding into all the mics with undesirable time offsets along with unwanted vibration noise to the subs which sounds bad or put subs on a separate send and eliminate all that and sound good
One argument against subs on aux, as I understand it, suggests that allowing dynamic adjustment of the sub level creates the potential for a system tuning problem as the effective crossover frequency is likely to change with the level of the sub. Is this really something to worry about? Thanks for the video! Looking forward to the next one, too!
That is definitely an interesting concern and it's important to put it into perspective. Assuming the time alignment and phase alignment between subs and the main PA is accurate and perfect at the crossover point and that the subs and main PA are not phase aligned at frequencies above and below the crossover point, then keeping them aligned would be beneficial and would require a somewhat precise volume level correlation. Additionally for this precise alignment to stay intact it would be mandatory that the subs and upper boxes are located in very close proximity to each other. If there is distance between the subs and top boxes then moving closer and farther away would alter that phase relationship for the listener much in the same way as altering the volume relationship between the two. So to keep things in perspective, the importance of not putting subs on a separate send is about the same as the importance of not having your subs at any distance located away from the top boxes. That said, the way I describe sending to subs in this video maintains the volume relationship between the subs and the top boxes as long as left and right Master level and the subwoofer Master level are adjusted together. All other level adjustments at the channel and subgroup level maintain the accurate correlation. Personally, I think that having distance between the subs and the main PA is an advantage and when that happens only a small sliver of the audience will see that proper phase alignment which I generally treat as fairly unimportant
Interesting to see a "High Pass" or "Band pass" filter of 30Hz to 80 Hz on the sub. This is strictly to remove "noise" , not considered audio from (20 Hz and below) from getting to the amp. Correct? Also wondering about the benefit of two, high pass filters on the tweeter/woofer setup? Can you not remove the high pass before the summing amp, and achieve the same goal? Or...does this stage represent the individual filters on each channel of a mixing console?
Most setups will have multiple high pass filters throughout the signal chain. Lots of gear has built-in high pass filters, either intentional or not intentional. If there was no high pass filter theoretically you could reproduce DC which would blow out your speakers without making sound. That said using too many iPass filters can negatively affect the sound quality of the low end and make it ringy and resonant. It's very normal to want to limit the low end below a certain point going to subs either because they can't reproduce those frequencies or there's no material down there of useful quality
Hi Dave ! Absolutely helpful and smart ! Just one thing - THE TRIANGLE ! I not understand what gear is this ? :) What im saw is some kind of ONE WAY crossover ? or ... Thank you !!! :)
Well, diodes do allow electricity to flow one way but only the positive or negative voltage. So a dioxide will cause massive distortion int the audio path. It's more like a preamp with no gain
A question about hipassed mics still sending low end to the subs: what if I just highpassed further? I usually high pass vocal mics around 200/250Hz & snare, HH, & overheads around 150Hz Would increasing the high pass filters create a similar result when sending LR to everything compared to separate sub sends?
Raising the high pass will reduce the amount of low frequencies from that input. But a high pass is just a filter that reduces the amount of low frequencies sent to the subs. A 12 DB per octave high pass set at 250, will be 12 DB down at 125, and 24 DB down at 63 HZ. So the high pass set at 250 is turning the lows down 24 DB that are going to the subs at 63 HZ With subs on an aux send you have the option to turn it down all the way so it can't get there from here. Now 24 DB is a good amount of drop but every single microphone on stage will add some low end to the subs, so the subs will see all the channels you want sent to them Plus low end crap from every single other microphone when you have subs on left and right. If the bass guitar amp bleeds into every mic on stage and you have 24 mics, you now have that bass guitar bleeding into the subwoofers at 24 different time delays depending on where the mics are positioned creating a blur of low end. Same with stage vibrations, wind, HVAC fan air, and handling noise. It may not be loud in some setups and could be quite loud in others but it definitely always will be there. I recommend testing and seeing if eliminating all that extra crap going to the subs cleans up your mix. I know for me it made a clear and audible difference plus it gave me more control and instead of high passing things much too high I can set the high pass wherever the instrument sounds best and even boost low EQ on that channel to warm it up and still not send signal to the subs on channel so they don't want sent to subs
Would there be any reason to not go "hybrid" with the crossovers? My main system is all active Xover, though the mains themselves actually have passive crossovers, currently being bypassed. If I never get even close to full output on those amps, using the internal crossovers would eliminate the need for 4x amps. I designed/set up a PA for another venue and used the passive Xovers in their line arrays, with active Xover for the subs. I did that to save them money and there's no obvious issues.
Yes as long as the crossovers can handle it hybrid can be quite good. For the microwedge I designed an EAW sells, they operate bi amp or passive, both modes work really well. Additionally I designed processor settings for the passive operation so that they sound identical or near identical to the active operation. The passive allows you to have more mixes use less amps and works really well. The same thing applies to main speakers and even the D&B J system and other designs operate with passive to the horns
@@DaveRat Thanks man! My mains are EAWs, good cabs. The amps are a little overkill but I could always just set my output limiters a little lower after making the switch. For such a busy guy, you are extremely good with engagement.
